Hydraulic governor for engines, turbines, and the like



"May 18 1926.

J. O. BOVING HYDRAULIC GOVERNOR FOR ENGINES, TURBINES, AND THE LIKE 2 Sheeffls-Sheet 1 Filed Feb. 1. 192;

May 18 1926. 1,585,529

J. o. ,BOVING HYDRAULIC GOVERNOR FOR ENGINES, TURBINES, ,AND THE 11m:

4 Filed Feb. 1, 1922- 2 Sheets-Sheet 2 Patented May 18,- .1926. I V UNITED STATES PATENT .OFFICE.

. I mns QBTENVIIBOVIING, OF LoNnbN, ENG Aivn: HYDRAULIC GOVERNOR FOR ENGINES, TURBINES, AND THE LIKE.

Application filed February 1, 1922. Serial No. 533,336.

This invention relates. to an improved ,Iappend drawings diagrammatically ilhydrauli'c governor for enginesiurbine's and lustrating my invention: the like prime movers. Figure 1 is a sectional view of a governor The object of the invention is to provide .in which the outlet passage for the oil is 0 a governor which shall be sufliciently sensithrough the differential piston;

tive to keep the speed variations of the Figure 2 is a sectional viewpf a overnor prime mover within small limits, while proin which the outlet passage for t e oil is viding suflicient force to overcome the frictaken through the cylinder casting and the tional resistance of the control gear of the outlet is controlled by a pi'stonvalve;

, 1o prime mover. Figure 3 shows a modification in which The invention consists in a governor comthe outletopening is controlled by a piston prising a hydraulic tachometer having a valve and a concentric sleeve.

cylinder, piston, spring, and a centrifugal Incar'rying the invention into effect in impeller driven by the prime mover, and one form the tachometer comprises a cen- 15 a co-operating hydraulic relay or servomotrifugal impeller 1 which is driven directly tor, the piston element of which operates or indirectly by the prime mover, a cylinder the control gear of the prime mover and 2 and'piston 3.' The impeller supplies oil whose position of equilibrium in its cyl- 1 o her liquid under pr ssure to h cyli 'inder is determined by the tachometer der thereby tending tomove the piston in 2 piston. one direction, the liquid pressure being The invention also consists in a governor counterbalanced by a spring 4, or by a of the kind above defined in which the servospring and dead weights, in such manner motor comprises a difi'erential pistonand that the piston moves a certain definite dis- .cylinder, a pump which continually suptance from its normal position when the plies liquid under pressure-to the cylinder speed of, the prime mover changes to a chamber of smaller effective piston area, an definite value different from the normal outlet passage from the cylinder chamber value. The servomotor comprises a cylinof larger efl'ective piston area, and a conder casing or the like having two coaxial stricted passage connecting the .two said bores of'difi'erent diameters, two pistons, or 30 chambers; the opening to the outlet passage a piston 5 and plunger 6, in fixed connection beingcontrolled by the'pistons ofthetachomwith each other forming a differential piseter and servomotor.- ton slidable in the said bores, and a pump The various parts are connected in such 7, whichmay be driven by the prime mover, manner that when the tachometer piston has supplying 011 under pressure to the cylinder 35 been moved a certain distance from its'norchamber 8 of smaller efiective piston area.

'mal position due to a change of speed of The differential piston is connected by-suitthe prime mover from its normal value, the able mechanism to the operating gear of piston element of the hydraulic relayis disthe prime mover. placed from its normal position, thereby In one convenient form, Figure 1, the operating the control gear so as to bring the pistons of the tachometer and servomotor speed of the prime mover nearer to its norare arranged coaxial andvertical, the tachommal value. eter cylinder 2 being above the larger cyl- The oil is delivered direct from the u inder 9 of the servomotor and integral thereto thecylinder chamber of smaller effective With- A Piston rod 1 fixed t0 n g al piston area, from which a passage, which with the tachometer piston 3 passes throu may be throttled, communicates to the chama stulfing-box in the'cylinder casing and .7 ts ber of larger effective piston area. When easily but practically fluid-tight in a centhe prime mover is running steadily the diftral axial hole 11 bored through the difierferential piston of the servomotor and the ential piston of the set vomoto I tachometer piston are at rest, the outlet When the prime mover is running steadily opening for the oil being of such amount at normal speed the pistons of the tachomthat the/reduction of pressure of the oil eter and servomotor are at or near the in flowinghthroughthe constricted passage middle positions of their respective strokes. between 1; e two cylinder chambers gives The circular edge 12 of the lower end of the 110 e ual total pressures on the two opposite cylindrical surface of the tachometer piston e ectivefsides of the difl'erential piston. I rod is then slightly above the upper circular -e r, r w VmuJi-T the hole 11 of the piston.

edge 14 of the axial hole through the differ-ential piston of the servomotor. This permits oil to escape through the said hole, reducing the intensity of pressure on the upper surface of the dilferential piston until the total downward pressure thereon is equal to the resultant upward pressure on the other surfaces of the differential piston. In this and other relative positions the tachometer piston rod and the dilferential piston co-operate to act as a valve, opening or closing the passage for the escape of oil. An adjustable screw throttle valve 13 is placed in the passage 15 between the two ends of the cylinder 9 to regulate the rate of flow of oil therethrough. The piston rod 10 is extended beyond the said circular edge 12 for the purpose of guiding it asit enters The extension may comprise a neck 16 of reduced diameter near the said circular edge, a cylindrical part 17 fitting the hole in the piston, and a tapered part 18; the said cylindrical and tapered parts being grooved longitudinally as at 19 to provide oil passages.

The cylinder casing is supported on a pedestal 20. The pe'destalsupports a wiper shaft 21 which is oscillated by the axial movement of the differential piston and transmits that movement by suitable means to the operating gear of the prime mover.

' A sump or tank 22 on the pedestal collects the oil escaping through the differential piston, and supplies the oil pump 7 which is suitably mounted on the pedestal or attached to the servomotor cylinder casing.

The action of the governor is as follows: \Vhen the prime mover is running steadily at its normal speed the parts are in equilibrium as hereinbefore-described. If, now, the speed of the prime mover increases, due tea reduction of the load, the tachometer piston and piston rod will be displaced into a new position of equilibrium. If the fluid presses on the upperside of the tachometer piston with 'suflicient force to overcome the upward pressure of the spring on the lower side thereof, as shown in the drawings, the said displacement will be downwards; the piston rod 10 enters the hole 11 of the dilferential piston and closes the oil passage therethrough. The oil being delivered by the pump 7 flows throughthe passage 15 and gradually forces the dilferential piston downwards until it comes to rest in such position that oil escapes through 'the central hole at the same rate as it is being supplied'by the pump: If, now, the speed of the. prime mover decreases, the tachometer piston and piston.

rod move upwards into a new position, the oil escapes more freely through the differential piston than it can pass the throttle aforesaid. Incidentally, the stroke of the tachometer piston may be made less than that of the servomotor piston.

In Figure 2 a piston valve 25 controls the outlet opening and is connected to a lever 26 the two ends of which are moved by the pistons of the tachometer and servomotor Jrespectively. In Figure 3 the piston 25 is coupled direct to the/tachometer piston 3,

and a concentric ported sleeve 26 is connected to the servomotor piston, and is slidable in the cylinder 27 coaxial with the tachometer cylinder 2. "With this arrangement the tachometer spring 4 may be made long relative to the stroke of the tachometer piston, which in turn may be made small relative to that of the servomotor piston, thereby keeping the speed variation of the tachometer, and therefore also of the prime mover, within small limits.

Having now described my invention what I claim as new and desire to secure by Letters Patent is 2-- 1. A governor for prime movers comprising ahydraulic tachometer constituted by a cylinder, a piston, a spring and a centrifugal impeller driven by the prime mover, a cooperating hydraulic servomotor. constituted by a differential piston and cylinder, a pump, a conduit between said pump and the cy inder space exposed to the smaller effective piston area, a constricted passage interconnecting the two cylinder spaces, and valve/means associated with one of said pistons coacting with an outlet port associated with the other of said pistons to produce a variable outletpassage from the cylinder space exposed to the larger effective piston area.

'posed, the outlet passage comprising a coaxial hole through thedilferential piston of the servomotor and a rod attached to the piston of the tachometer being slidable therethrough for the purpose of controlling the amount of opening.

' In testimony whereof I have signed my name to this specification.

JENS ORTEN BOVING.

2. A governor .as claimed in claim 1, in 

